Fuel metering control for fuel injection systems

ABSTRACT

A fuel metering control device for use in controlling the position of an adjustable shuttle stop in a fuel distributing unit employed in a fuel injection system for internal combustion engines automatically controls the fuel-air mixture in response to throttle position as well as air pressure in the intake manifold.

United States Patent 1191 1111 3,820,332 Crowe 1 1 June 28, 1974 1 FUELMETERING CONTROL FORFUEL 2,827,852 3/1958 Links 123/139 AM INJECTIONSYSTEMS 3,650,257 3/1972 Soltay et a1 123/140 CC [75] Inventor: EugeneMelroy Crowe, Corte M d ,C l'f. I a era a] 1 Primary Examiner-Carlton R.Croyle 1 Asslgneer ph y Hammond. a Assistant Examiner-Warren Olsen parInterest Attorney, Agent, or Firm-Merriam, Marshall, Shapiro 22 Filed:May 21, 1973 211 Appl. No.: 362,573

Related US. Application Data [63] Continuation of Ser. No. 150,688, June7, 1971, [57] ABSTRACT abandoned.

[52] us. CLW 60/13 R, 123/139 AM 123/140 CC A fuel metering controldevice for use in controlling 51 1m. 01. .f. F02b 37/04 an adjustableShuttle in a fuel of Search" AM 140 tributing unit employed in a fuellfljCCtlOl'l system for 60/13 internal combustion engines automaticallycontrols the fuel-air mixture in response to throttle position as [56]References Cited well as air pressure in the intake manifold.

UNITED STATES PATENTS 2,670,724 3/1904 Reggio 123/140 cc 4 Claims, 4Drawing Figures PATENTEI] Jul 28 H74 FIG. 4

INVENTOR EUGENE CROWE BYM,MJA Mf/%J ATTORNEYS FUEL METERING CONTROL FORFUEL INJECTION SYSTEMS This is a continuation of application Ser. No.150,688, filed June 7, 1971, now abandoned.

SUMMARY OF THE INVENTION The present invention relates to a fuelmetering control device. In general, it concerns a control device foruse in automatically controlling the air-fuel mixture in a fuelinjection system. More particularly, it pertains to a fuel meteringcontrol device for use in controlling the position of an adjustableshuttle stop in a fuel distributing unit employed in a fuel injectionsystem for internal combustion engines.

BACKGROUND OF THE INVENTION Fuel injection systems are employed'withinternal combustion engines used in passenger cars as well as racingcars. As compared to carbureted engines, engines employing fuelinjection systems generally offer the potential advantages of improvedfuel economy at equivalent performance or, conversely, increasedperformance for equivalent consumption. In addition, fuel injectionsystems when properly operated afford a practical means for decreasingexhaust emissions. In racing cars, fuel injection systems are, ofcourse, generally used in attempts to improve performance. In suchinstances, turbochargers or superchargers are also commonly employed inorder to obtain greater horsepower output from the engine bypressurizing the air supplied to the intake manifold of the engine. Onecommonly employed fuel injection system, sometimes referred to as theLucas fuel injection system, employs a fuel metering or distributingunit which receives fuel at a constant pressure (for example, 100 lbs.per sq. inch) and the metering unit distributes the fuel to the fuelinjectors. The metering and distributing unit employs a reciprocatingshuttle which, in association with a rotor and suitable inlet and outletports, provides each cylinder of the engine with an injection of fuel,the amount of which is determined by the axial movement of the shuttle.The axial movement of such a shuttle is determined by an adjustableshuttle stop. The position of the adjustable shuttle stop is generallycontrolled by a device which changes the position of the shuttle stop inresponse tochanges in throttle position. US. Pat Nos. 2,807,252,3,452,729, 3,487,821 and 3,491,738 for example, disclose such fuelinjection systems employing fuel distributing units which employ areciprocating shuttle, an adjustable shuttle stop, and means forcontrolling the adjustable shuttle stop.

Turbocharged or supercharged engines are of course, operated over arange of conditions including low air pressure (i.e., no boost or lowboost) and high air pressure (i.e., high boost) conditions. As a result,unless the air-fuel mixture is changed to compensate for such changes incondition, at certain times the engine receives an over-rich fuelmixture while at other times it may receive an over lean fuel mixture.In attempts to overcome this problem, and to obtain the correct mixturefor all RPM and power ranges some. turbocharged fuel injected engineshave employed two separate fuel control systems or circuits, one ofwhich is a manually operated circuit for controlling the air-fuelmixture when the engine is operating at low speed, low boost conditions.The other or second circuit which operates in response to throttlechanges is for high speed, high boost conditions. However, these latersystems do not permit a smooth transition when going from low speed, lowboost to high speed, high boost conditions, and as a result, an engineso equipped often manifests an RPM range where the engine does notreceive the correct air-fuel mixture. Accordingly, there is a need for afuel metering control device which will provide automatic control of theair-fuel mixture at all conditions of engine operation.

DESCRIPTION OF THE INVENTION According to the present invention, thereis provided an improved fuel metering control device particularlyuseful, for example, with turbocharged engines. The device provides ameans for automatically controlling the fuel-air mixture by adjustingthe volume of fuel in the mixture in response to both changes inthrottle position and changes in air pressure in the intake manifold.The present invention will be better understood by reference to theaccompanying illustrative drawings in which:

FIG. 1 is a fragmentary perspective view of a turbocharged fuel injectedinternal combustion engine equipped with a fuel metering control deviceof the present invention.

FIGS. 2, 3 and 4 are all fragmentary elevational view showing therelative positions of certain parts of the control device.

Referring to the drawings, there is shown an internal combustion engine10 provided with twin turbochargers 11 and 12. Turbochargers 11 and 12supply pressurized air to air box or plenum chamber 13 via conduits l6and 17 respectively. Engine 10 is further equipped with a fuel injectionsystem generally comprising fuel injector stacks l4 and fuel distributor20. Pressurized air from plenum chamber 13 is supplied to injectorstacks 14 and from the stacks 14 to engine 10 via intake manifold 15.Fuel distributor 20 is pulley mounted to engine 10 by a half speed jackshaft (not shown). The other end of fuel distributor 20 is provided witha control device housing 21. Housing 21 supports spindle or shaft 23.Engine 10 is further equipped with an air motor 30 affixed to engine 10by a mounting bracket 31. Air motor connecting rod 32 connects orfastens to lever or arm 26 by connecting or fastening means 33. Airmotor 30 includes a pressure sensing conduit (not shown) which providesmeans for communicating intake manifold air pressure to air motor 30.Throttle linkage means 36 connects arm or lever 35 which is fixadlyattached to shaft 23 in such a manner that when lever 35 is moved bythrottle linkage means 36, shaft 23 rotates.

As can be best seen in FIGS. 2, 3 and 4, an intermediate portion ofshaft 23 is provided with an eccentric cam 24. Arm 26 is preferablyprovided with a bushing 25 to provide a bearing surface between arm 26and cam 24. Stops 28 and 29 which are shown as integral to housing 21limit the travel of arm 26. Arm 26 is provided with a profiled surface27 which abutts adjustable shuttle stop 22. The size and shape ofeccentric cam 24 as well as the size and shape of profiled surface 27 ofarm 26 will, of course, depend in part upon the particular fueldistributor 20 with which these elements are used. Those skilled in theart will be able to develop the desired sizes and shapes of both cam 24and profiled surface 27 for any particular application by routineexperimentation using, for example, dynamometer readmgs.

Air motor 30 is a device which is capable of sensing pressure andproviding a mechanical displacement proportioned thereto. Such devicesare known in the art and generally comprise, for example, a bellows-typediaphram with an attached piston which may be spring resisted and whichwhen air pressure is applied'results in the piston moving or displacinga distance proportional to the applied air pressure.

In operation, air motor 30 is used as part of the fuel metering controldevice of the present invention to sense the pressure intake manifold 15and to provide a displacement of connecting rod 32 an amountproportional to the pressure sensed. Rod 32 in turn mechanicallyactuates arm 26 and rotates arm 26 about shaft 23 as illustrated by thechange in position of arm 26 in FIGS. 3 and 4. As is apparent from thedrawings, such change in position of arm 26 causes its profiled surface27 which abutts shuttle stop 22, to move stop 22, and thus change thedistance which a reciprocating shuttle (not shown) can travel. lnchanging from the position shown in FIG. 3 to that shown in FIG. 4, theprofiled surface 27 of arm 26 has moved stop 22 downward and thusreduced the distance that the shuttle can travel and therefore alsoreduced the quantity of each fuel increment leaving distributor 20. Sucha change would be initiated by air motor 30 sensing a decrease in intakemanifold pressure.

The change in positions of lever 35, shaft 23, cam 24 and stop 22 fromthe positions illustrated in FIG. 2 to the positions shown in FIG. 3depict the control action which occurs when a decrease in throttleactuates a reduction in fuel. As is apparent from the above descriptionthe control device of the present invention provides means forautomatically adjusting the fuelair mixture in response to both changesin throttle position and intake manifold pressure.

While the present invention has been described and with reference tocertain preferred illustrated embodiments obvious modifications with thespirit and scope of the invention will be apparent to those skilled inthe art.

What is claimed is:

1. A fuel metering control device for usein regulating the position ofan adjustable shuttle stop in a fuel .distributing unit employed in afuel injection system for an internal combustion engine and said enginehaving an intake manifold for feeding fuel to the engine and also havingan exhaust manifold for removing exhaust gases, and said fuel meteringcontrol device being responsive to both intake manifold pressure and theposition of a throttle linkage mechanism, said control devicecomprising:

an air motor adapted to continuously sense the pressure in the intakemanifold and having a connecting rod extending therefrom to provide amechanical displacement proportional to pressure changes within saidintake manifold;

a profiled cam member abutting the shuttle stop and being rotatable toreciprocate the shuttle stop;

a rotatable cam shaft having a cam portion located eccentrically withrespect to the cam shaft, and further said cam portion providing abearing for rota-- tional movement of the profiled cam member wherebyrotation of. said cam shaft provides vertical displacement of theprofiled cam member; lever means connecting the profiled cam member andthe rotatable cam shaft with the connecting rod of the air motor and thethrottle linkage v whereby movement of either or both the throttlelinkage and the connecting rod will produce responsive reciprocalmovement of the shuttle stop.

tion engine having a fuel injection system.

1. A fuel metering control device for use in regulating the position ofan adjustable shuttle stop in a fuel distributing unit employed in afuel injection system for an internal combustion engine and said enginehaving an intake manifold for feeding fuel to the engine and also havingan exhaust manifold for removing exhaust gases, and said fuel meteringcontrol device being responsive to both intake manifold pressure and theposition of a throttle linkage mechanism, said control devicecomprising: an air motor adapted to continuously sense the pressure inthe intake manifold and having a connecting rod extending therefrom toprovide a mechanical displacement proportional to pressure changeswithin said intake manifold; a profiled cam member abutting the shuttlestop and being rotatable to reciprocate the shuttle stop; a rotatablecam shaft having a cam portion located eccentrically with respect to thecam shaft, and further said cam portion providing a bearing forrotational movement of the profiled cam member whereby rotation of saidcam shaft provides vertical displacement of the profiled cam member;lever means connecting the profiled cam member and the rotatable camshaft with the connecting rod of the air motor and the throttle linkagewhereby movement of either or both the throttle linkage and theconnecting rod will produce responsive reciprocal movement of theshuttle stop.
 2. The control device of claim 1 in which said lever meansincludes a first lever member connecting the profile cam member with therod extending from the air motor; and; a second lever member connectingthe throttle linkage with the rotatable cam shaft.
 3. The control deviceof claim 1 in which said cam portion of the rotatable cam shaft isintegrally formed with the cam shaft.
 4. The control device of claim 1in which the internal combustion engine is a turbo charged internalcombustion engine having a fuel injection system.